Method of and apparatus for testing the teeth of gears and the like



May 22,1928; 1,670,906

o. e. SIMMONS METHOD OF AND APPARATUS FOR TESTING THETEETH O F GEARS ANDTHE LIKE Filed Oct. 20, 1926 'r Sheets-Sheet 1 INVENTOR May 22, 1928.1,670,906 0. G. SIMMONS I METHOD OFQND APPARATUS FOR TESTING THE TEETHOF GEARS AND THE LIKE Filed Oct. 20, 1926 7-Sheets-Sheec 2 14 VLIVTORIMay 22, 1928; J 1 1,670,906

\ 0. G. SIMMONS METHOD OF AND APPARATUS 'FOR TESTING THE TEETH 0F GEARSAND THE LIKE File d Oct. 20, 1926 A TSh'eet s-Sheet s INVENTOR,

I May 22, 1928.

O. G. SIMMONS METHOD OF AND APPARATUS FOR TESTING THE TEETH OF GEARS ANDTHE LIKE Filed Oct. 20, 1926 '1 Sheets-Sheet" 4 INVENTOR,

May 22, 1928. E 1,670,906

O. G. SIMMONS METHOD OF AND APPARATUS FOR TESTING THE TEETH OF GEARS ANDTHE LIKE Filed Oct. 20, 1926 7 Sheets-Sheet 5 7 "3% L- 53 g 2111 I 44 tMay 22, 1928. 1,670,906

- o. e. SIMMONS METHOD OF AND APPARATUS FOR TESTING. THE TEETH 0F GEARSAND THE LIKE Filed Oct. 20, 1926 'r Sheets-Sheet '6 INVENTOR May 22,1928.

O- G. SIMMONS METHOD OF AND APPARATUS FOR TESTING THE TEETH OF GEARS ANDTHE LIKE Filed 001;. 20, 1926 7 Sheets-Sheet 7 INVENTOR Patented May22,1928.

UNITED STATES PATENT OFFICE,

OLIVER G. SIMMONS,

OF LAKEWOOD, OHIO.

METHOD OF AND APPARATUS FOR TESTING THE TEETH OF GEARS AND THE LIKE.

Application filed 0mm 2 My invention relates to improved method of andapparatus for testing surfaces intended to conform to any spiral curveswhich maybe generatedby a point having a uniform movement angularlyaround a fixed point and also along a tangent I having its center atsaid point, i. e., involutes of circles and the epitrochoids thereof.The device of the present invention is designe particularly for testingthe teeth of gears. and the like in which the gears to be tested areprovided with involute curves to a given evolute, a specific circle, allright hand curves of which are parallel and, vice versa, all left handcurves are parallel, so that if a point is moved along a line tangent toand uniform with the rotary movementof said evolute, the point willdescribe the involute curve to said evolute, andthe point will havemoved along a tangent line, for each revolution of the evolute, adistance corresponding to the measure of the perimeter of sai evolute.--This is in accordance with the law of the involute curve which is statedas follows:

The involute of any evolute has a constant lead which, when measured ona line tangent to the evolute, the generating The foregoing inition ofsuch a curve may lows: w

The inv lute curve is the resultant of the uniform movement of a pointyalong a straight line tangent 'to a given circle and the angularmovement of a line about the periphery of a circle'uniform with themovement of this point and over an are equal in length to the distancetraversed by this ,point. This is more fully set forth in the applicantsarticle, The law of the involute curve published in the AmericanMachinist issues of November 23rd and November 30th, 1922. f

Heretofo're inkapparatus of this character the method pursued hasnot-provided that the point referred to be placed with precisioncoincident with the line tangent to the evodjust lute. The necessarymechanism to a said point to said tangcntline is lacking In all devicesand apparatus hereintofore proposed. 4

The main object of the invention, therefore, resides in the method ofand apparatus 'isequal to the perimeter o evolute.

being true,

the correct def:

be given as fol- I evices not 0, 1926. Serial No. 142,866.

for setting a theoretical mathematical point, said point being definedas the normal'position of the contact point of a deflectable contactmember engageable with a surface to be tested, the contact point of saidmemher being preferably a point on the periphery of a circle formed'by aplane surface on the contact member intersecting a conical surfacethereof at right angles to the axis of the conical surface in a linetangent to the evolute. If thepoint referred to is not dis posed asstated an error will be introduced determined by the difference in themagnitudeof the measure of the side adjacent, and the hypothenuse, in aright-angle tri-' angle; the measure of the opposite si e 0 saidright-angle triangle being equal to the measure of the distance themathematical point is belowor above the evolute. If the mathematicalpoint is above or below,the line, a minus error will (1 be introduced,the magnitude of the measure as referred to above.

heretofore proposed f it is obvious that in the inspection departmentsof manufacturing establishments, a

chaotic condition Wlll. result as experienced by the applicant andbymanufacturers using the applicants methcd of and apparatus to which theywork when manufacturing their roduct, which; product, if later checkedon provided to operate on the method in the invention herein disclosed,may result in'fictitious errors of inspection with the result referredto.-

A further object of the invention resides in the means for adjusting themathematical point previouslyreferred to with respect to evolutes of theinvolutes under consideration. Another objectof the invention resides inthe means provided for the adjustment of the point in a planeperpendicular to the axis of the evolute and also in a plane arallel tothe axis of the evolute.

A still furt -1er object of the invention resides in means to cause themathematical point to move uniformly along a line tangent to and withthe rotary movement 0 the evolute. i

Another object of the'invention resides in the means for accuratelypositioning tape securing means with respect to a line tangent Otherobjects of the 1nv en-- to an evolute. tion reside in the meanshereinafter described and referred to in theappended claims.

With the above and still other objects in view the invention comprisesbroadly the method of and apparatus for measuring the accuracy ofinvolute curves to a given evolute or base circle by determiningprecisely the measure of the magnitude of error on a true involutecurve; and, of measuring the magnitude of the error, if any exist,between parallel involutes generated from the same evolute or basecircle, as illustrated in the accompanying drawings hereinafterdescribed and particularly set forth in the appended claims, togetherwith such variagrammatic view forming a part of this specification.

zing a base circle tlon and modification thereof as will be apparent tothose skilled inthe art to which the invention appertains. Referenceshould be made to the accompanying drawings Fig. 1 ratus.

Fig. 2 is a rear shown in Fig. 1.

Fig. 3 is a right end elevation of the apparatus shown in Fi 1, viewbeing taken from the right hand slde of the in .the drawing, Fig. 1.

i 4 is a sectional elevation, 44 of Fig. 1, 1051111}: in the directionof the arrow.

Fig. 5 is an end view of the adjustable tape screw housing member.

is a front elevation of the appaelevation of the apparatus Fig. 6 is afragmentary side view of Fig. 5.

Fig. 7 is a side elevation of theadjustable tape screw housingmember,showing fragmentary portion of the .tape screw and tape attached theretoin assembly position. Fig. 8 isa front elevation and partly diaof thegraduated end plates showing the adjustable ta e screw housing as itwould be adjusted t inch pitch diameter gear'for the like, hav- Idetermined by a pi essure angle of 14% degrees. Theaxis of 'tliespind'lein this view is shown as a broken line and bears a definite relation tothe graduated lines shown as wi-llbelater referred to.

Fig. 9 is an end-viewof Fig. 8.

Fig.10 is a geometricl view illustrating an evolute .017, basej cir'clewith its involute viewed from the son viewing-the drawing, Fig. 11.

be journalled in person view- .tapered portion 9 of ereon for a six toFig. 1 except in this acmeoc tary portion of the pinion shaft,hand-wheel,

graduated dial, zero parts.

Fig. 14 is a plan View of the dial adapted to rotate with the hand-wheeland illustrates particularly the indentations which are adapted to forma seat for the spring actuated plunger carried by the zero plate.

Fig. 15 is a schematic view illustrating the position of the i'nvolutecurves of the teeth of gears and the like with respect to themathematical point.

The numeral 1 indicates the base of the apparatus which, as will benoted, is circular in form and adapted to receive the flange 2 of thebed 3 of the apparatus. The ase 1 is provided with the rubber tips 1',adapting it to rest on a able appliance. The fiange'2 is adapted to thebase 1 so that the apparatus may be swivelled-bodilyin base 1 aspractice requires. For example, it is decidedly easier to swivel theapparatus in base. 1, if for any reason it is desired to present therear side of the machine, as shown in Fig. 2, to the operator, than itwould be to lift it bodily for the purpose aforesaid.

The bed 3 is provided with the bore 4, see Fig. 4, adapting the said bed3 to l1ave.journalled therein the spindle 5. The spindle 5 is providedwith oil grooves 6 and enlarged portion 7, forming-a shoulder, .50 thatsaid spindle 5 may be secured against end-play by means of the clampingnut 8 as shown. The spindle 5 plate and component table or other suitisfurther provided with the tapered portion 9, adapting it to receive thebase circle 10, which is provided with one or more steps; as forexample, base circle step 10 andbase circle step 10". The base circlemember 10 is fixedly secured to said the spindle shaft 5 by means'of thewasher 11 and butterfl nut 12. The bed 3 is further provided wit thesaddle 13, which is provided with V-ways 14, Figs. 1 and 4, adapting itto receive'the slide 15 and to be moved laterally in said saddle 13 bymeans of the track "16 'securedto said slide by means of the screws 17,see

Fig. 1, and the inion' 18 intermeshing with said rack 16am fixedlysecured to shaft 19 to which is also fixedly securedhand-wheel 20, shaft19 being bosses 21, forming a. portion of the saddle 13. If hand-wheel20 is rotated, therefore, slide 15 will be caused to "move in. saddle 13in the direction of the arrow 22, Fig. 1, or in a direction oppositetothat shown by ar row 22, dependent upon the direction of rotation ofhand-wheel 20.

. The zero portion of the boss 21 and is provided with journalled inintegral plate 23 is fixedlysecured to a a zero line 24. The dial 25 isjournalied on end 38 till said dial being provi ing beyond an extendedportion of the hand-wheel 20,

'ded with the thumb screw 26 so that as hand-wheel is rotated, dialwillrotate therewith, dependent upon whether the thumb screw 26 isfixed, to secure and make of 'dial 25 and hand-wheel20, a unitary part.with graduations 27 for a purpose to be later described and is furtherprovided with indentations 28 which are adapted to form a seat for thespring-actuated plunger 29, which, as shown, is located in zero plate23, also for a purpose to be later described.

The slide 15 is provided with end portions 30 and secured thereto arethe graduated end plates 31 by head screws 32, see Figs. 1, 2 and 3. Theend plates 31, as shown, are provided with ielongated slots 33, see Fig.8, adapting said end plates to reccivethe tape screw housing 34 and befixedly securedthereto by means of the washer nut 35 having threadedengagement with the circular threaded portion 34 of said tape screwhousing 34, in a position, preferably predetermined vertical asdetermined by zero line 36-on said housing 34 and graduated lines 37 onsaid end plates 31. The housing 34 is provided with the extended portion34 which is provided with a slot 34, said housing 34 being adapted toreceive the threaded screw member 38, one of which is adapted to receivethe loop 39 of the tape 40. The other end of the threaded screw member38 is adapted to receive the knurled thumb wheel 41. Thread screw member38 is further provided with the pin 38", which is fixedly sccuredthereto, having end portions projectits outer surface to engage the slot34, so that as thumb wheel 31 is rotated the threaded screw 38 will havea longi tudinal rectilinear movement only, said pin 38 preventing anytendency of the threaded screw member 38. fromerotating, thus tension isplaced on the tapes 40, by the tightening of thumb screw 41. ashereinafter referred to.

The tapes 40, as shown in Fig. 2, are secured at the other end of-sameby means of a button-head screw 42 to bne step of the basecircle 10. InFigs. 2 and 4 the tape is shown as fastened to the larger step 10*.

t will be observed, with reference tolFig.

2, that tape from the right'side-of the device substantially semicirclesbase circle step 10 on the left side of the base circle 10. whereas tape40 from the left sidelof the apparatus substantially semicircles theright side of step 10 of the base circle 10. The slide 15 through themedium of tapes 40 and the base circle 10 and correlated partspreviously described, will cause the spindle 5 to rotate. Therotat'ionof spindle 5, it will he observed, will be in accordance with thediameter of the step 10".

tapes and The dial25 is prov ded means of the fillister are accuratelylocated at a above the axis 43 of the spindle 5, the distance, It hasbeen found in practice and can be readily demonstrated that since thetapes 40 are of a given thickness, allowance will have to be made in thediameter of the base circle 10 for the measure of the thickness of thethe actual periphery of the true evolute or base circle liesintermediate the sides of the tape-40. Therefore the measure of thediameter of any evolute or base circle, designed for use in thisapparatus, shall be the theoretical evolute or* base circle diameter,minus the thickness 40. of the tapes 40. It follows from the above thatthe slide 15 will move uniformly with the rotary motion of an evolute orbase circle, the effective diameter of which corresponds to the diameter of the evolute" or base circle. By effective diameter taken atthe median points of the tapes intermediate the sides of same. In otherwords, the diameter plus the thickness of one tape, or conversely, thetheoretical base circle diameter which has been reduced an amount equalto the thickness of the tapes. For example, if the thickness of the tape40 is meant that diameter 1 is .005 inch and the theoretical base circle1 diameter is 3.75876 .inches,,the actual diameter of'the base circle 10will be 3.75876 inches minus .005 inch, but the effective base circlediameter will be the theoretical evolute or base circle diameter of3.75876 inches.

From the foregoing it will be understood that the thickness 40 of thetapes must be accurate throughout the length thereof and to a givendimension. This also applies to the actualdiameter of .the base circle10,

so that the effective diameter as referred to will be correct. tice thata variation in tapes of .0001 inch or anequivalent-error It has beenfound in prac'-- I the thickness of the in the actual diameter of thebase circle or evolute 10 will cause an error in the readerably towithin .000025 inch.

From this statement of fact it is obvious that the tapes 40 must betruly disposed tangent to base circle 10 and that the line of tangencymust be parallel to path of travel of slide 15. To enable the operatorto adjust the tapes parallel to path of travel of slide 15, and to thecorrect height above the axis 43 of spindle 5, within close limits oferror, the endplates 31 aregraduated, as shown in Fig. 8. The zero line36 of the housing is located on each side of the flat portion 34? ofsaid housing and the lines 37 given distance the measureof whichcorresponds to onehalf the theoretical diameter of the evolute or base.circle.- For. example, in a four inch pitch diameter gear or gear shapercutter having a 20 degree pressure angle, the evoti lute or base circlediameter would be equal gle, the base shaper cutter.

inches, the apparatus has been constructed in certain size machines tosuitthe A has beenadapted to'check 4 and 6 inch pitch use; that is tosay,

requirements of the trade. lhe end plates of Fig. 8, therefore, areillustrated in one application of this-pract'ce, in which the machinediameter gear shaper cutters, being graduated,for pressure angles most.commonly in teen and one-half degrees and twenty degrees.

- from the evolute E for Referring to Fig. 10 it will be noted'that theinvolute curve! I has been generated spire or one revolution of theevolute E. In

5, the single revolution referred to, and in accordance with the law ofthe involute, the generating point, as for example, P, will I have movedfrom position 0 along a line T tangent to the evolute tovthe position Pas shown. The measure of the-distancefroni O to position P will equal,as previonsly stated, the perimeter of. the evolute E; in the Yspecific'example illustrated by Fig. 10, this is found to be 4.75000inches. In this geometric view the plane intersecting axis of spindle isshown extended by 'dot and dash line projection to the right of theevolute in the plane of the drawing and the measure of the distancebetween the axis of the spindle in and the tangent line Cl, is one-halfthe di-.

ameter of the evolute or equal to .755985 inch. The point 1?, therefore,must at all titttimes lie .in the line T, evolute.

The point P has been previously defined as a point on the intersectionof a plane intersecting a cone transversely thereof. It is obvious thatthe point Pin a plane intersecting the cone must-lie in the line T,which is'the linertangentnto the evolute, and if it be as: surned thatthe plane referred. to passes through the line tangent to said evolute,but

a line tangent to the through accident, wear of needle point, or

- otherwise, the point l is moved a distance 5 X above the line Ttangent to evolute, it is;

pitch diameter,

For ,convenience of mamp'u gear shaper' pressure angles of fouradistance of one obvious that an error having a magnitude which willequal the measure M has been introduced and this .error it is seen isthe difference between the length of the adjacent side A and the lengthof side OP in the right-angle triangle OBP. The apparati'is thereforeWould show a minus reading error dependent upon the magnitude of themeasure M and conversely, if the point I" was below the tangent line T,the distance, X, the

magnitude of the error M would be in the same order m that the errorwould be minus.

In the apparatus forming this invention means have preferably beenprovided to adjust point P,'and the point P has preferably been providedfor in the -practical application as being in the intersection of theconical surface 44 and the plane surface 45, so

that the line of intersection can be main- A tained, as for example bygrindingconical surface 44.

, It is important in an apparatus of this 7 character thatthe magnitudeof the error be magnified as much as possible. consistent with goodpractice. For. this purpose, therefore,-tl1ere is preferably providedthe amplifying lever arm 46, see Figs. 1, 3. 4, 11 and 12, provided withthe needlepoint 47, lower extremity of which is provided with theconical surface 44, and the plane surface 45,

inn lever arm "46 is pivoted at F, being journalled on the stud 48,which is fixedly secured-atone end thereof to the 'vertical slide 49,said amplifying lever armflt be ing journalled on the'other end of saidstud 48 and secured against displacement there from. by means of theflat-head screw 50.

previously referred to and shown enlarged in Fig. 10. This amplify Theamplifying lever arm 46, thereforeficf) may be oscillated a slightamount'each side of the-center sectional line 4-4, Fig. 1. To preventexcessive movement of this amplifying lever arm, studs 51 are providedoneach side thereof to arrest its movement. 'llo the upper portion ofslide 49, dial indi cators 52 are secured by any suitable means,

one on each side of the amplifying lever arm 46, and adjusted in suchposition so that when the point '0 of the amplifying lever arm 46coincides with the vertical center sectional line 44, the pointingneedle in each indicator will register zero.

Referrin to Fig. 4, the spindle 5 is fur-,

ther provi ed with the extension 53, on

which there is adapted to be secured, by

any suitable means, a circular disc, not.

shown, the diameter of which corresponds to the theoretical evolute orbase circle diameter. lhe slide 49 is adapted 'to be moved up or down bymeansof the handwheel 54 and screw55, having threaded en gageinent withthe nut 56, said nut being secured to traverse slide 57. In setting theneedle point 4? the correct height above the illustrates the position.of

46, needle point v for slide modification and structural difference inthe means provided to cause the i the end plate 31 on axis 43 of thespindle 5, it is only necessary to place the aforesaid disc of properdiam veter on theextension 53, of the spindle 5, and raise or lower theslide 49 until the surface 45 of the needle point 47 contacts therewith,after which the slide 49 may be locked in said position by any suitablemeans, as for example, in the ordinary way of tightening gib screws. Thetraverse slide 57 is adapted to be moved transversely of the slide 15,by means of the hand-wheel 58 being secured to screw 59, which hasthreaded engagement with nut 60 fixedly se cured to said slide 15. Thevertical slide 49 and the traverse slide 57, therefore, provide means toadjust needle point 47 vertically or longitudinally of the axis 42 ofthe spindle 5. This adjustment is made for the reasons heretofore statedhnd for the additional reason of-adaptability by which an embodiment ofthe apparatus in a machine is given a range, enabling a given machine totest the invo ute'curves of gears and the like of various sizes withinits capacity.

The schematic fview of Fig. 15 clearly curved surface of the tooth andfragmentary portion of the amplifying lever arm 47 and mathematicalpoint described.

shown in Figs. 11 'and12 that just described, except 44 in contact asThe apparatus is identical with slide 15 to move in the saddle 13.

Referring to Fig. 12 it willbe noted that the right hand side of themachine is provided with the extension 61 in which is journalled thescrew 62. This screw has threaded engagement with the nut 63, said nutbeing fixedly secured to saddle 13., Screw 62 is provided, as shown,with the large hand-wheel 64 having handles 65. Hand-wheel 6% maybefixedly secured to said screw 62 1 by any suitable means, as for exampleby a woodrufi key and nut- 66 having threaded engagement with endportion of the screw 62.. End plate 31 is further provided with theextension 67, on the outer portion of which the zero line '68 has beenengraved. The'handwheel 6% .is provided with the graduation 69 shown, sothat as hand-wheel (id is rotated from one graduation point 69 to theother, with reference to zero line 68, slide w 15 will be caused to move.001 inch.

lltwill be apparent that each tooth face of a gear, is a cam surface andthat the device of the present invention is adapted to he used fortesting any cam surface intended to. conr curve of the class whih'eludes the involutes of circles. ifthe tracing point P be adjusted aboveor below the tangent to the base circle member," the point/P, ifundetracing point.

the involute is represented f by a which do not conform orm to a uniformlead spirai ute of the base circ e, the prolate epitroch 1d having abase circle larger than the involute and auniform lead along a tangentto its base circle less than that of the involute of its base ,circleand the curtate epitrochoid having a smaller base circle and a leadalong a tangent to its base circle greater than the involute of its basecircle. Such an adjustment of the may be employed in testing helicalgears 0' the type produced by the method disclosed in my co-pendingapplication Serial No. 178,021.,"filed for method of cutting helicalgear teeth, which are of epitrochoidal form in planes perpendicular totheir axes.

The apparatus described has been found to be very sensitive and smoothin operation and in practice incident to scientific laboratory work hasenabled physicists and others to minutely investigate tooth contour andthe rolling action of involute gears.

Having thus described my, invention I claim: i

-1. The herein described method of testing curved surfaces whichconsists in accurately positioning in a line tangent to a given basecircle, a theoretical mathematical point which is represented by thenormal position of the actual contact point of a detlectable contactme1nber engageable with the surv face to be tested, and imparting to thesurlated as to cause said theoretical point to trace the theoreticalcurve and said actual contact pointto be deflected by portions of saidsurface which do not conform to said theoretical curve. 4

2; The herein described method of testing involute surfaces whichconsists in accurate 1y positioning in a line tangent to the evolute, atheoretical mathematical point which the normal position of the actualcontact point of a defiectable coritact' member engageable with thesurfacevto be tested, and imparting to the surface and contact memberrotational and linear movements, about the'axis of the evolute and alongsaid tangent line, so correlated as to cause said theoreticai point totrace the theoretical curve and said actuai contact point to bedeflected by portions of said surface uto said theoretical curve, andindicating the magnitude of the deflection of the contact member duringthe passage of said contact point over said surace. v

3'. In gear testing apparatus, a contact member having 'a tooth engagingportion formed by a conical face and a plane face transverse to the axisof the cone and intersecting the conical surface at an acute all-' Mar.24, 1927;

i ed for linear movement laterally of. the spingle'to provide an edgefor point contact with a gear tooth, i

4. gear testing apparatus, a contact member having a flat end face and aconical surface flaring toward said end face and a having its axisperpendicular to said end face,,the intersecting conical and planesursaid member faces providing an edge for point contact with a geartooth;

.a work spindle, a supporting member mount- 5. In apparatus of thecharacter set forth,

ed for linear movement laterally of the spindle, a contact memberyieldably mounted on and having a contact point which. normally occupiesa fixed position, with respect to said member, means for turna ingsaidspindle and for imparting a correlated linear movement to saidsupporting; member laterally of the spindle, means for} indicatingdeflections of the contact memberl j from normal position, and meansforadjust- 'ing said contact member t said member and having, a contactpoint.

7 owards and from the axis of the spindle. i a

'6. In apparatus of the'character set forth,

a work spindle, a supporting member mountdle, a contact member yieldablymounted on which normally occupies a fixed position with respect to saidmember, means for turn-- ing said spindle and for imparting a correlatedlinear movement to said member laterallyoi the spindle supporting meansfor indicating deflections ot the contact member from normalposition,means for adjusting said contact member toward and from v the axis ofthe spindle, and means for ad-' justing-the contact memberlongitudinally of said spindle.

7. In an apparatus'of the character set forth, a spindle adaptedtoreceive a gear to be tested, a slide mounted to move trans- Q versely oithe axisof saidspindle,means for imparting a turning movement to thespindle and for moving a slide uniformly with the rotary motion of thetheoretical base cir cle of the "car on the spindle, a contact memberyielda ly mounted in the'sli e and hav- 1 a spindle journaled in thebase, a verti slide mounted on the first mentioned slide, an n ing acontact point, the normal position of which represents a mathematicalpoint which, moveswith the slide, and means to adjust the contact memberto position said mathematical point in a line tangent to saidtheoretical base circle. I

8. ln apparatus of the cha'racterset forih, al

amplifyingclever mounted on the vertical slide, said amplifying deverhavinga contact point, the normal position of which represents amathematical point fixed with respect to the first mentioned slide and 4meansior imparting movement to the first v mentioned slide and rotarymovement to the a slide adaptedcto move on said base later- 'ally of thespindle, a vertically adjustable amplifying lever, mounted on" saidslide, said lever having a contact point, the normal position of whichrepresents a mathematical point fixedwith respect to said slide, meansconnecting the base circle member and slide to move the slide uniformlywiththe-rotary movement of the base circle member and means foradjusting said amplifying lever alo'nga line paralleLto the axis of thespindle.

10.111 an apparatus of the character set lforth, a. spindlegjournaled inthe-base, a -,oi the spindle, a vertical slide mounted on. the firstmentioned slide, means for adjusting said vertical slide, meansconnecting" the first mentioned slide with said base circle member forcausing said slide to move unimember, an amplifying lever carried bysaid vertical-slide, said amplifying lever having a contactpoint,'the'n0rmal position of which represents a mathematical pointfixed with slide mounted .to move fon said base laterally form'ly withthe rotary movement of said respect to said first mentioned slide and aplurality ,of amplifying lever. I

11. In an apparatusof the character described, a spindle journaled indial indicators actuatedby-said 7 the base, a I

slide mounted on said base for movement "causing the slide amathematical point means connecting the, normal position fixed withrespect to the slide, means for adjusting the "amplifying levertowardand from the spindle to position said mathematical point in atangent, of the theoretical base Y circle which is parallel to thedirection of movement to the slide, and a dial indicator actuated bysaid amplifying lever.

12. In an apparatus of the character set forth, a basega spindlejournalled in said base, a member having a base circle mounted on saidspindle, a slide carried by said base and adapted to move in arectilinear path transversely tapes secured atone end thereof to saidbase circle, and meansfor fixedly securing the other ends of said tapesin adjusted sitionv to accommodate said base circle, so

that said tapes will lie in a plane tangent to nit of the axis of saidspindle,

spect to the axis of Said base circle, said plane being paralleltoforth, a base, a flange journalled therein, a.

saddle and bed integral with said flange, a spindle carried by the bed,a slide carried by said saddle, said slide carrying a horizontal slideand a vertical slide, said vertical slide being provided with anamplifying lever arm and a plurality of dial indicators, a needle pointcarried by said amplifying lever arm adapted to be positioned withresaid spindle along a vertical line and also along a line at rightangles thereto, a member having a base cit cle mounted on said spindle,said spindle being further adapted to receive the Work, connecting meansbetween said spindle and slide carried by the saddle, so. that as saidslide is moved in a rectilinear path the spindle is caused to rotate.

14. In an apparatus of the character set forth, a bed, a saddle mountedon the bed, a

shaft carried by the saddle, a slide carried by the saddle, a racksecured to said slide and an intermeshing pinion fixedly'secured to saidshaft, a to said pinion shaft, a zero platefixedly secured to saidsaddle, a graduated dialmounted on said hand-wheel, a springactuate'd.plunger journalled in said zero plate and.

provided with a zero hand-wheel fixedly secured engage indentations insaid dial for the purpose set forth.

15. In an apparatus of the character set forth, a bed, a saddle integraltherewith, a shaft carried by the saddle, a slide carried by said saddleand means to move said slide with respect to said saddle, said meanscomprising a rack fixedly secured to said slide, an intermesliing pinionfixed on said shaft, and a hand-wheel fixedly secured to said shaft forthe purpose set forth.

' 16. In an apparatus of the character set forth, a bed, a saddleintegral therewith, a slide carried by said saddle and means toadaptedto move said slide with respect to said saddle,

said means comprising an end plate fixedly secured to said slideprovided with two extensions, a screw journalled on one of saidextensions, said screw being provided with a graduated dial, the otherextension being line to coincide with the periphery of said graduateddial, a nut fixedly secured to said saddle and having threadedengagement with said screw, so that said slide may be moved with respectto said saddle, the measure of which is determined by the unit ofmeasure of the graduations on said dial.

Signed this 19th day of October, 1926.

OLIVER G; SIMMONS.

